Is it possible to change the textures of the player/Tux by giving him different skins or textures? If so, how can I do that? Can I/Is it possible to make an add=on that changes Tux's skin? If you cannot do any of these things, how would you/would you add them into the game and why/why not? Thank you!

But I mean changing the textures in a way that the developers would approve of, such as an in-game Tux texture changer or changing his skin in the level editor. Would the current developers approve of a way to change Tux's texture in any way? I am also asking if it is possible to create a separate addon for this. Thanks!